A video cartoon consists of a sequence of image frames to be played one after another. A cartoon character refers to the image drawn to resemble human, animal or other object within an image frame of the video cartoon. Photographic or drawn face of human or other animal may be superimposed on each cartoon character. Each image frame with superimposed faces within a video cartoon is currently produced manually as follows:
1. The cartoon characters for the image frame have to be available first. They may be produced beforehand by any other methods.
2. Each face to be superimposed have to be selected from among all the available faces to be the correct face and to show the required facial expression of its corresponding cartoon character for the image frame.
3. Using an image editing computer software, each face to be superimposed has to be resized and rotated so as to fit its corresponding cartoon character for the image frame.
4. Using an image editing computer software, each face to be superimposed is clipped, positioned and pasted onto the corresponding cartoon character as its face, for the image frame.
5. The cartoon characters with the superimposed faces may then be superimposed onto an optional background image to produce the final image frame.
Using video editing computer software, all the image frames are then combined into the final video cartoon, optionally adding background audio. The manual production of video cartoons with superimposed faces is time consuming and tedious as explained as follows:
1. For each image frame of the video cartoon, the superimposed faces need to be manually selected, resized, rotated, clipped and positioned, so as to fit the corresponding cartoon characters. A background image may also need to be added. This process will generally takes 20 seconds or more for each image frame, even for a very experience and fast computer software user. Even if it takes only 20 seconds for each image frame, it will take 40 minutes (2400 seconds) to produce a one-minute (60 seconds) duration video cartoon with 120 frames at a frame rate of 2 frames per second.
2. If the superimposed faces have to be changed, the process has to be repeated for each affected image frame.
The invention aims to automate and speed up the production of video cartoons with superimposed faces, by using distributable video sequences of cartoon characters, drawn according to the guidelines of the invention. With the guidelines of the invention, the invention is able to detect and recognise the original faces of the cartoon characters with high accuracy, and superimpose the corresponding user-provided faces over them correctly. With the invention, different users can provide different user-provided faces and backgrounds to the same distributable video sequence of cartoon characters to produce many different final video cartoons easily and rapidly.
International Patent WO02052565 is another method for automatic video production. However, it is different from the invention as it uses “distributable styles” for editing user-provided videos automatically instead, and offers no specific provision to detect and recognise the faces within the videos.
International Patent WO96002898 is a method for drawing the mouth of a user-provided face automatically within a video, while China Patent CN1710613 is a method for drawing the facial expression of a user-provided face automatically within a video. Both methods are different from the invention as they focus on drawing the user-provided face according to audio inputs, and offer no specific provision to detect, recognise or replace the faces within a video.
Japan Patent JP2002008057 and US Patent 20030228135 are both methods for replacing a real human face within a video with a user-provided face automatically. The invention is different from them in the following ways:
1. The invention replaces one or more cartoon characters' faces, drawn according to the guidelines of the invention, while Japan Patent JP2002008057 and US Patent 20030228135 are designed to replace a single real human face.
2. The invention has high accuracy of detecting the cartoon characters' faces because the cartoon characters' faces are drawn according to the guidelines of the invention. Japan Patent JP2002008057 and US Patent 20030228135 do not have such a high accuracy because computerised detection of real human face is not perfect.
3. The invention recognises and replaces one or more cartoon characters' faces with their corresponding user-provided faces with high accuracy. Japan Patent JP2002008057 and US Patent 20030228135 focus on drawing the face of a single person with no provision for accurate face recognition.